package io;

import java.util.HashMap;

import java.util.Random;

public class SecretCode {

HashMap<String, Integer> keyMap = new HashMap<>();

void addKey(String user) {

if (!containsUser(user)) {

Integer key = new Random().nextInt();

keyMap.put(user, key);

}

}

boolean containsUser(String user) {

return keyMap.containsKey(user);

}

public Integer encode(String user, Integer code) {

Integer key = null;

if (!containsUser(user)) {

addKey(user);

}

key = keyMap.get(user);

return code ^ key;

}

public Integer decode(String user, Integer code) {

return encode(user, code);

}

public static void main(String[] args) {

SecretCode coder = new SecretCode();

Integer code = 23334;

Integer encode = coder.encode("John", code);

System.out.println(encode);

Integer decode = coder.encode("John", encode);

System.out.println(decode);

}

}